U.S. patent number 7,279,659 [Application Number 11/216,314] was granted by the patent office on 2007-10-09 for non-food warmer appliance.
This patent grant is currently assigned to Western Industries, Inc.. Invention is credited to John M. Gagas, Daniel E. Stair, II, David J. Zeier.
United States Patent |
7,279,659 |
Gagas , et al. |
October 9, 2007 |
Non-food warmer appliance
Abstract
A non-food warmer apparatus includes an enclosure having sides,
a top, and a bottom defining a chamber. A drawer structure has a
support member to support objects. The drawer structure is coupled
to the enclosure for movement between a retracted position to warm
the objects within the chamber and an extended position external to
the chamber to permit access to the objects by a user. A heating
system heats the chamber and a ventilation system moves air through
the chamber. A user interface includes inputs to control a
temperature and a humidity within the chamber. A detection system
includes sensors to detect a condition within the chamber and
provide a signal. An electronic control system is coupled to the
enclosure and interfaces with the heating system, the ventilation
system, the user interface, and the detection system so the objects
in the chamber can be maintained at a desired temperature.
Inventors: |
Gagas; John M. (Milwaukee,
WI), Stair, II; Daniel E. (Cedarburg, WI), Zeier; David
J. (Town of Delafield, WI) |
Assignee: |
Western Industries, Inc.
(Milwaukee, WI)
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Family
ID: |
35995167 |
Appl.
No.: |
11/216,314 |
Filed: |
August 31, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060049172 A1 |
Mar 9, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60622185 |
Oct 26, 2004 |
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60606396 |
Sep 1, 2004 |
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Current U.S.
Class: |
219/400; 219/385;
219/392; 219/407; 219/521 |
Current CPC
Class: |
F24C
7/08 (20130101); F24C 15/18 (20130101) |
Current International
Class: |
F27D
11/00 (20060101); F23M 7/00 (20060101); F26B
19/00 (20060101); F27D 1/18 (20060101); F27D
11/02 (20060101); F27D 19/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Gagas et al., U.S. Appl. No. 11/216,443, titled "Warming
Apparatus", filed on Aug. 31, 2005 (Specification, Claims and
Abstract 44 pgs., 16 pgs. of drawing, 60 total pgs.). cited by
other .
Wolf, Warming Drawer Use & Care Information, bearing a date
indication of Jan. 2004; 16 pgs. cited by other .
Wolf, Warming Drawer Installation Instructions, bearing a date
indication of Nov. 2004; 12 pgs. cited by other .
Gagas, John M., U.S. Appl. No. 11/147,511 titled Factory Preset
Temperature Warming Appliance; filed on Jun. 8, 2005. cited by
other.
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Primary Examiner: Pelham; Joseph
Attorney, Agent or Firm: Boyle Fredrickson
Parent Case Text
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This Application claims the benefit of priority under 35 U.S.C.
.sctn. 119(e) of U.S. Provisional Patent Application No. 60/606,396
titled "Warmer Drawer" filed on Sep. 1, 2004, and U.S. Provisional
Patent Application No. 60/622,185 titled "Non-Food Warmer Drawer"
filed on Oct. 26, 2004 which are incorporated herein by reference
in their entirety.
Claims
What is claimed is:
1. A non-food warmer apparatus, comprising: an enclosure defining a
chamber and having an opening; a drawer structure extendable from
the chamber and movably coupled to the enclosure by guide members;
at least one support structure coupled to the drawer structure and
configured to hold non-food objects within the chamber; a heating
element configured to provide heat to the chamber; a ventilation
system operable to move air within the chamber; at least one sensor
configured to provide a signal representative of a condition within
the chamber; a user interface capable of receiving an input from a
user and generating an output; an electronic control system
operable to receive the signal representative of a condition within
the chamber and the output from the user interface and to control
operation of the heating element and the ventilation system; and a
drive system operable to move the drawer structure between
positions; and a heating element integrated with the support member
to promote warming of the objects.
2. The non-food warmer apparatus of claim 1 wherein the electronic
control system comprises a positive temperature coefficient of
resistance controller.
3. The non-food warmer apparatus of claim 1 wherein the user
interface comprises a touch pad device having a plurality of input
elements.
4. The non-food warmer apparatus of claim 3 wherein the touch pad
device comprises an operating technology selected from the group
consisting of a piezo electric device, a capacitance device, an
inductive device, a resistance device, an infrared device, a high
frequency pad-less soft touch device, a pad-less touch digital
encoder, a magnetic switch, a field effect device, a charge
transfer device, a hall effect device, a transistor, and a micro
encoder.
5. The non-food warmer apparatus of claim 3 wherein the touch pad
device comprises a membrane switch.
6. The non-food warmer apparatus of claim 3 wherein the input
elements comprise at least one preprogrammed operating
functions.
7. The non-food warmer apparatus of claim 3 wherein the
preprogrammed operating functions include at least one of a
preprogrammed time and a preprogrammed temperature stored in a
microprocessor of the electronic control system and selectable by a
user through one of the input elements on the user interface.
8. The non-food warmer apparatus of claim 1 wherein the user
interface is operable remotely from the enclosure to permit a user
to control operation of the warmer apparatus from a remote
location.
9. The non-food warmer apparatus of claim 1 wherein the at least
one sensor comprises a sensor selected from the group consisting of
a temperature sensing device, a humidity sensor and an infrared
temperature sensing device and the condition is at least one of a
temperature and a humidity in the chamber.
10. The non-food warmer apparatus of claim 9 wherein the
temperature sensing device is selected from the group consisting of
a thermostat, a thermal protector, a thermal cutoff, a thermal
switch, a thermocouple, a PCB thermostat, a time delay relay, a
bulb and capillary device, a cold control, a bimetallic device, a
pressure switch, resistance temperature detector, a snap action
switch, and a thermistor.
11. The non-food warmer apparatus of claim 1 further comprising a
display device configured to provide information to a user.
12. The non-food warmer apparatus of claim 11 wherein the display
device comprises a display panel having technology selected from
the group consisting of light emitting diodes, liquid crystal
display, plasma, dot matrix, and vacuum fluorescent display.
13. The non-food warmer apparatus of claim 11 wherein the display
device is integrated with the user interface.
14. The non-food warmer apparatus of claim 1 wherein the
ventilation system comprises a fan configured to circulate air
within the chamber.
15. The non-food warmer apparatus of claim 1 wherein the
ventilation system comprises a plurality of vent apertures in the
enclosure and a variably positionable damper to regulate a flow of
air through the vent apertures.
16. The non-food warmer apparatus of claim 15 further comprising a
vent actuator operable to position the damper in response to a
signal from the electronic control system.
17. The non-food warmer apparatus of claim 16 wherein the vent
actuator comprises at least one of a solenoid drive device, a screw
drive device, a gear drive device, a motor driven device, a
cylinder driven device, a biasing member, a bi-metal device, an
electromagnetic device and an electronically actuated device.
18. The non-food warmer apparatus of claim 15 wherein the vent
apertures are located proximate a top of the enclosure and a fan is
located proximate a bottom of the enclosure and configured to draw
air into the chamber through the vent apertures.
19. The non-food warmer apparatus of claim 1 wherein the enclosure
comprises a door and the ventilation system comprises a plurality
of vent apertures in the door.
20. The non-food warmer apparatus of claim 1 wherein the door
comprises an inside panel and an outside panel and the vent
apertures are arranged for flow of air between the inside panel and
the outside panel.
21. The non-food warmer apparatus of claim 1 wherein the support
structure comprises an elongated member having a cross sectional
shape selected from the group consisting of an inverted V, a Y, an
X, and a U.
22. The non-food warmer apparatus of claim 1 wherein the support
structure comprises a plurality of perforations.
23. The non-food warmer apparatus of claim 1 wherein the support
structure comprises at least one of a pan and a rack.
24. The non-food warmer apparatus of claim 1 wherein the user
interface is rotatably coupled to the enclosure for movement
between a use position and a concealed position.
25. The non-food warmer apparatus of claim 1 wherein the user
interface comprises a remote control device.
26. The non-food wanner apparatus of claim 1 further comprising a
door pivotally coupled to the enclosure that when opened permits
extension of the drawer structure.
27. A non-food warmer apparatus, comprising: an enclosure defining
a chamber and having an opening; a drawer structure extendable from
the chamber and movably coupled to the enclosure by guide members;
at least one support structure coupled to the drawer structure and
configured to hold non-food objects within the chamber; a heating
element configured to provide heat to the chamber; a ventilation
system operable to move air within the chamber; at least one sensor
configured to provide a signal representative of a condition within
the chamber; a user interface capable of receiving an input from a
user and generating an output; an electronic control system
operable to receive the signal representative of a condition within
the chamber and the output from the user interface and to control
operation of the heating element and the ventilation system; a
drive system operable to move the drawer structure between
positions; and a door capable of sliding into the enclosure.
28. An electronically controlled non-food warmer apparatus,
comprising: an enclosure having sides and a top and a bottom
defining a chamber; a drawer structure having at least one support
member to support objects thereon, the drawer structure coupled to
the enclosure for movement between a retracted position to warm the
objects within the chamber and an extended position at least
partially external to the chamber to permit access to the objects
by a user; a heating system operable to heat the chamber; a
ventilation system operable to move air through the chamber; a user
interface having a plurality of inputs configured to control at
least one of a temperature and a humidity within the chamber; a
detection system configured to detect a condition within the
chamber and provide a signal representative of the condition; and
an electronic control system coupled to the enclosure and
interfacing with the heating system and the ventilation system and
the user interface and the display device so the objects in the
chamber can be maintained at a desired temperature; wherein the
heating system includes a heating element integral with the support
member.
29. The non-food warmer apparatus of claim 28 further comprising a
drive system operable to position the drawer structure within a
travel range between the retracted position and the extended
position.
30. The non-food warmer apparatus of claim 29 wherein the drive
system comprises a screw drive system.
31. The non-food warmer apparatus of claim 30 wherein the
electronic control system interfaces with sensors that detect a
stop point and transmit a control signal to the drive system.
32. The non-food warmer apparatus of claim 28 further comprising a
container communicating with the chamber and configured to receive
an aromatic material capable of imparting a scent to the
objects.
33. The non-food warmer apparatus of claim 28 further comprising a
mobile pedestal coupled to the enclosure.
34. The non-food warmer apparatus of claim 28 wherein the
ventilation system comprises a variable speed fan controlled by the
electronic control system and operable to move air within the
chamber.
35. The non-food warmer apparatus of claim 28 wherein the
ventilation system comprises apertures formed in at least one of
the sides, the top and the bottom, and a damper device operable to
increase ventilation in the chamber by uncovering the apertures and
operable to decrease ventilation in the chamber by covering the
apertures.
36. The non-food warmer apparatus of claim 35 wherein the apertures
are formed in the top and the heating system comprises at least one
heating element positioned adjacent to the apertures.
37. The non-food warmer apparatus of claim 28 wherein the heating
element comprises a ceramic heating device.
38. The non-food warmer apparatus of claim 28 wherein the
electronic control system comprises at least one preprogrammed
temperature set point and at least one time duration for selection
on the user interface by a user.
39. The non-food warmer apparatus of claim 28 wherein the detection
system comprises at least one of a temperature sensor, a humidity
sensor and an infrared temperature sensor.
Description
FIELD
The present invention relates to warming appliances, and more
particularly to non-food warming appliances. The present invention
relates more particularly to a non-food warmer drawer.
BACKGROUND
Non-food warming drawers such as towel warmer drawers of
conventional design are typically constructed as closed boxes of
single wall or double wall construction with insulation or air in
between, with front doors providing access to a sliding drawer
horizontally aligned to access non-food items or objects (such as
towels, robes, dishes, restaurant-ware, etc.) within the interior
of the box. The front door(s) are often fixed in a vertical plane.
Heating of the interior of the box is usually accomplished by a
single cal rod (sheathed heating element), axial fan heaters, hot
water, oil heat, or contact type heaters. The heat sources are
typically arranged to conduct heat across an item in the drawer
with the use forced air arrangements (such as a heater/fan or
heater-blower combination) or by radiant heat arrangements where
heat is radiated upwards from a heated pipe or a cal rod as a way
to warm the interior of the box and to warm the non-food objects,
such as towels, inside the box. However, warmer drawers for
non-food objects that use such forced air methods in a closed
chamber tend to have certain disadvantages. For example, a forced
air heater/fan combination having a heating element in front of the
fan and blowing hot air inside the enclosure tends to cause the
heating element to continually heat up and draw excessive
electrical current. In such arrangements, the heater usually
receives only internal air as supplied by the fan and the heater
remains in a mode of high output. The resulting high temperature is
typically directed at the top or sides of the objects often causing
hot spots that can burn the objects (such as heat sensitive objects
such as towels and the like). The forcing of the air into the
chamber also tends to result in air moving past the object without
sufficiently warming the objects. In addition, direct contact with
the heating element, if not shielded, can cause overheating,
discoloration or burning of the objects. Further, in the event that
the fan should stop or if air is somehow restricted, the fan can
fail due to overheating, which may result in a "runaway" heating
element. Accordingly, such conventional arrangements often require
that a "fail-safe" type switch must be added which elevates the
cost of the non-food warmer drawer.
According to other conventional designs, towel warmers with
generally "airtight" enclosures have also been used. The airtight
chambers typically use only the air inside the box, re-circulating
it and heating (or reheating) the re-circulated air. However, these
type of airtight chambers have certain disadvantages. For example,
temperature overshoot and undershoot problems from the heating
elements typically occur, resulting in temperatures within the
airtight chambers that are too high and cause objects within the
chamber such as towels to become too hot and discoloring (e.g. heat
discoloration, scorching, burning, etc.). In order to protect the
towels, many attempted solutions to reduce the temperature within
the chambers have been used, but have not resulted in a
satisfactory solution. In addition, the air within the airtight
chambers poses other detrimental issues for the user. For example,
because such warmers generally do not exhaust the heated air, any
odor or smell from the objects tends to remain within the enclosure
and adversely affect other objects. In some cases the smell may be
so strong that the use of warmed objects such as towels becomes
undesirable.
Other conventional non-food warmer drawers use a "pan" type of
arrangement with a heating element (such as cal rod or the like)
below the pan. However, such a conventional non-food warmer drawer
design is essentially converting a conventional food warmer drawer
to a non-food warmer application, which also tends to suffer from
certain disadvantages. For example, when heating non-food objects
such as towels, these pan-type warmer drawers tend to result in
only the bottom of the towel getting warm and usually do not
provide a desired uniform heating of the object(s). In some
instances, before the towel's inside surfaces can be warmed, the
exposed outer surfaces may burn or suffer other types of
degradation associated with exposure to high temperature. In some
conventional pan-type applications, a plate has been added within
the box in an attempt to defuse the heat and prevent burning of the
object(s). However, this purported "fix" usually only slows the
warming of the object(s), which results in the object(s) needing to
be in the pan for a longer period of time. When warming objects
such as towels, the thermal energy necessary to penetrate the towel
folds is a generally known problem with the use of pan (or shelf)
type warmer drawers. Typically, when warming a stack of objects
such as towels, as the "stack" of towels in the warmer drawer
increases, the amount of thermal energy needed to heat towels to
the desired level also increases.
The conventional non-food warmer drawers also suffer from other
disadvantages. For example, the sensors used to detect the
temperature of the objects in the warmer drawers are typically
capillary tube device or the like, in which expanding gases within
the tube, as temperature increases or decreases, transfers force or
relaxes force to a mechanical switch, causing the switch to close
or open for supplying electrical current to, or turning current
off, to the cal rod or axial fan. The typical response time for
these types of controls tends to be undesirably slow and often
results in overshoots and undershoots in temperature. These
characteristic temperature ranges and swings in conventional
non-food warmer drawers, from power on and off cycling, tend to
result in such conventional warmer drawers being designed to
provide lower temperatures and longer times needed for warming of
the objects (particularly for heat sensitive objects such as towels
and the like). In addition, the undershoot of the temperature
usually results in the user does not obtaining a desired
temperature for the object. Thus the desired effects of receiving a
properly warmed object, such as a warm towel to the skin and the
ability to drive moisture out of a towel are reduced.
The conventional non-food warmer drawers also tend to suffer from
certain other disadvantages. For example, certain conventional
non-food warmer drawers often locate the heating elements with a
combined fan (heater/blowers) on the top and sides of the warming
chamber, and provide a cal rod (used in varying patterns) in the
bottom of the box to provides radiant heat. The radiant heat tends
to rise slowly, warming from the bottom to the top of the chamber.
This radiant heat usually produces "hot spots" when reaching a pan
or plate positioned above it. Such temperature hot spots are
generally due to the radiant heat source being strongest (hottest)
near the cal rod and decreasing in temperature as distance away
from the cal rod increases.
The conventional non-food warmer drawers also tend to suffer from
certain other disadvantages. For example, varying temperature
levels within the box tend to cause difficulty in controlling and
maintaining the temperature of the object. In some instances,
temperature stratification or "layering" prevents even and uniform
heating of the objects. In addition, startup times to attain the
desired temperature in the box can be long due in part to the cal
rod design. For example, too much heat too fast and the bottom of a
heat sensitive object such as a folded towel will burn before the
other parts of the towel reach the desired temperature. The
conventional warmer drawers usually attempt to compensate for such
problems by providing longer startup times. However, these long
startup times generally prevent a user from simply "turning the
warmer drawer on", inserting a towel, and achieving an acceptably
warm object in a reasonably short period of time. These
conventional warmer drawers usually rely on startup times that are
undesirably long in an effort to stabilize the temperature inside
the box and bring the objects to a safe temperature without
overheating. These types of conventional warmer drawers depend on
the user accepting undesirably long startup times before using the
object. If rushed, the object may not reach a desirable temperature
and it can feel unacceptably cool to the touch. Further, as the cal
rod cycles, temperature overshoots and undershoots typically result
in the temperature on the object being too warm or too cool
(depending on when the object is retrieved from the box).
The conventional non-food warmer drawers also tend to suffer from
certain other disadvantages. For example, many conventional warmers
drawers use knobs and slides to "set" and control mechanical
switches for selecting the temperature for the objects. Such
mechanical switches tend to have undesirable inaccuracies in their
setting and the repeatability of a setting. The disadvantages of
such mechanical switches tend to be due in part to the design of
the non-food warmer drawer and method of heating, but also due to
the inherent inaccuracy of the mechanical switches themselves.
Mechanical control switches generally exhibit hysteresis, which
contributes to inaccuracies in the ability of the control device to
obtain a set point or repeat a function. For example, this can be
seen in some conventional warmer drawers by turning the control
switch to the right and stopping at a set point; then for
comparison, turn the same mechanical switch past the desired set
point and then turn the control to the left stopping at the set
point. Both actions end with the same set point indicated on the
switch but the resulting temperature in the box is often different.
The inherent inaccuracies with the mechanical switching devices and
controls tends to exacerbate the effects of temperature overshoots
and undershoots and the resulting temperature variations
experiences by the object. In order to compensate for (or mask)
such inaccuracies, many conventional warmer drawers apply control
selections that indicate low, medium, and hot (or the like), rather
than a specific temperature setting. In such applications, a user
generally cannot see the set point differences from one use to the
next and may wonder why one day the object is warm and then another
day the object is cool when presumably using the same selected
settings. Temperature swings as much as 30 degrees or more are
believed to occur in such instances have been seen and detract from
the ability to provide accurate, rapid and uniform heating of
non-food objects.
The conventional non-food warmer drawers also tend to suffer from
certain other disadvantages. For example, conventional warmer
drawers are typically designed for "built-in" installations, such
as to cabinetry, or to a wall, or into another appliance, which
tends to limit the available uses for the warmer drawer. The
conventional warmer drawers generally do not permit usage as a
freestanding unit, or as a mobile unit, or under a cabinet (e.g.
suspended or the like), or in areas that do not have the ability to
support a structural frame.
Therefore a need exists for a non-food warmer drawer in which more
accurate and controlled heating of objects (e.g. towels, restaurant
ware, etc.) is accomplished. There also exists the need for an
accurate method of controlling the operations and settings of the
non-food warmer drawer. There also exists a need for the controls
of the non-food warmer drawer to be less susceptible to
environmental influences. There also exists a need for a display
device to permit a user to be able to view/see the operation,
temperature indication(s), set point functions, and view of the
contents of the chamber. There also exists a need for a non-food
warmer drawer capable of remote control operation. There is a
further need to accurately apply and control heat within the
chamber of the non-food warming drawer. There is also needed for a
non-food warmer drawer such that it can be used in any desirable
location to suit the particular needs of a user.
Accordingly, it would be desirable to provide a non-food warming
appliance such as a non-food warmer drawer, with any one or more of
these or other advantageous features.
SUMMARY
The present invention relates to a non-food warming appliance
having an enclosure defining a chamber and a heating apparatus to
change the temperature inside the chamber. A support structure
supports a non-food object inside the chamber and a user interface
associated with the enclosure controls at least the heating
apparatus. A control system interfaces with the heating apparatus
and user interface, and operates to control the heating apparatus
in response to a signal from the user interface so that a non-food
object supported by the support structure in the chamber is
maintained at a pre-determined temperature.
The present invention also relates to a non-food warmer apparatus
with an enclosure defining a chamber and having an opening and a
drawer structure extendable from the chamber and movably coupled to
the enclosure by guide members. At least one support structure is
coupled to the drawer structure to hold non-food objects within the
chamber. A heating element provides heat to the chamber and a
ventilation system operates to move air within the chamber. At
least one sensor provides a signal representative of a condition
within the chamber and a user interface receives an input from a
user and generates an output. An electronic control system receives
the signal representative of a condition within the chamber and the
output from the user interface and controls operation of the
heating element and the ventilation system.
The present invention further relates to a non-food warmer
apparatus having an enclosure having sides, a top, and a bottom
defining a chamber. A drawer structure has a support member to
support objects. The drawer structure is coupled to the enclosure
for movement between a retracted position to warm the objects
within the chamber and an extended position external to the chamber
to permit access to the objects by a user. A heating system heats
the chamber and a ventilation system moves air through the chamber.
A user interface includes inputs to control a temperature and a
humidity within the chamber. A detection system includes sensors to
detect a condition within the chamber and provide a signal. An
electronic control system is coupled to the enclosure and
interfaces with the heating system, the ventilation system, the
user interface, and the detection system so the objects in the
chamber can be maintained at a desired temperature.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of an exemplary embodiment of a non-food
warming appliance configured as a warmer drawer, with a door
extended from an enclosure, the drawer including a rail hanger
support, structure.
FIG. 2 is a side sectional view of the non-food warming appliance
illustrated in FIG. 1 with the drawer (including to objects to be
warmed) in the enclosure chamber and illustrating an exemplary air
flow through the warmer drawer.
FIG. 3 is a block diagram of an exemplary embodiment of a power
circuit for a non-food warming appliance having an electronic
controller and including a humidity control circuit and sensor.
FIG. 4 is a block diagram of an exemplary embodiment of a detector
circuit for a non-food warming appliance having an electronic
controller and including an infrared temperature sensor.
FIG. 5 is a block diagram of an exemplary embodiment of an
electronic controller for a non-food warming appliance.
FIG. 6 is a partial front view of an exemplary embodiment of an
inverted "V" shaped rail hanger support structure for a non-food
warming appliance, with a cloth, for example, a towel, draped over
the rail hanger.
FIGS. 7A-D are partial perspective views of exemplary embodiments
of support structures for a non-food warming appliance.
FIG. 8 is a partial side view of an exemplary embodiment of a
non-food warmer appliance including a pan configured to hold wet
objects.
FIG. 9 is a sectional side view of the pan illustrated in FIG. 8
along the line 9-9.
FIG. 10 is a perspective view of an exemplary embodiment of a wire
rack configured for use with the pan illustrated in FIG. 8.
FIG. 11 is a perspective view of an exemplary embodiment of a
non-food warming appliance configured for one of a wall and cabinet
installation.
FIG. 12 is a perspective view of an exemplary embodiment of a
non-food warming appliance configured for a stacked unit
installation.
FIG. 13 is a perspective view of an exemplary embodiment of a
non-food warming appliance configured for an under-counter
installation.
FIG. 14 is a perspective view of an exemplary non-food warming
appliance configured to couple to a stand structure which can be
movable, as facilitated by several devices.
FIG. 15 is a perspective view of the front door of an exemplary
embodiment of a non-food warming appliance.
FIG. 16 is a side view of an exemplary embodiment of a non-food
warming appliance with the drawer extending from the cabinet and
illustrating exemplary placement of several components.
FIG. 17 is a detailed view of sensor arrangement for a powered
drawer structure in a non-food warming appliance according to an
exemplary embodiment.
FIG. 18 is a bottom view of the non-food warming appliance
illustrated in FIG. 16.
FIG. 19 is a perspective view of an exemplary embodiment of a
non-food warming appliance associated with another appliance and
controllable remotely with a remote control unit.
FIG. 20 is a partial perspective view of an exemplary embodiment of
a non-food warming appliance illustrating alternative venting from
the cavity. (arrows depict air flow.)
FIG. 21 is a side view of the venting illustrated in FIG. 20.
FIG. 22 is an illustration of an exemplary embodiment of a user
interface for a non-food warming appliance.
FIGS. 23A-23C are partial side views of a rotating display for the
user interface touch control panel illustrated in FIG. 22.
FIGS. 24A-24B are partial side views of an alternative rotating
display for the user interface touch control panel illustrated in
FIG. 22.
FIG. 25 is a sectional side view of an exemplary embodiment of a
non-food warming appliance, including a powered drawer.
FIG. 26 is a detailed view of an exemplary embodiment of the
powered drawer illustrated in FIG. 25.
FIGS. 27 and 28 are bottom views of alternative embodiments of a
non-food warming appliance illustrating coupling and motion of the
door for the appliance.
FIG. 29 is a plan view of an exemplary embodiment of a venting
apparatus powered with a venting actuator.
FIG. 30 is a plan view of the venting apparatus illustrated in FIG.
29 illustrating a position different from that illustrated in FIG.
29.
FIG. 31 is a plan view of an exemplary embodiment of a venting
actuator of a screw drive type.
FIG. 32 is a plan view of an exemplary embodiment of a venting
actuator of a gear device.
FIG. 33 is a plan view of an exemplary embodiment of a venting
actuator of a solenoid drive.
DETAILED DESCRIPTION
According to the illustrated embodiments, there is disclosed a
warming apparatus (shown and described as a non-food warmer drawer
10) controlled by an electronic control system to provide improved
chamber temperature control, rapid heat-up, improved temperature
set point repeatability and minimal temperature variation from a
desired set point. The electronic control system of the warmer
drawer is shown to interface with (among others) a detection system
having various sensors (e.g. temperature, humidity, infrared,
scanners, electrical current, etc.), a heating element(s), a
ventilation system, a display device and a user interface to enable
a wide variety of desirable and advantageous features. For example,
the warmer drawer is shown as a modular device that is adaptable
for use in a wide variety of locations and environments and with
other appliances, fixtures or structures. The warmer drawer (when
in use) is intended to use a continuously adjustable amount of
power in a heating element to maintain a more precise control of
temperature within the chamber (rather than conventional and
less-precise "on-off" type devices, however, the electronic control
system could be configured for use with conventional heating
elements and sensors to reduce swings in temperature). The warmer
drawer is also shown to include a ventilation system that may be
actuated by various technologies to regulate the flow of air, heat
and/or moisture throughout the chamber. The warmer drawer is also
shown to include a display device configured to display information
to a user related to operation, temperature, functions, times or
other control parameters for the warmer drawer. The display device
is configured to display text (stationary or scrolling) and graphic
images or illustrations. The warmer drawer is also shown to include
a user interface (locally controlled and/or remote-controlled) to
facilitate operation (e.g. selection of inputs, setting changes,
start, stop, hold, etc.) of the warmer drawer by a user. The warmer
drawer is further shown to have a temperature-controlled internal
chamber that is accessible by access through a door or panel (e.g.
"reach-in" etc.) or by a movable portion (e.g. movable holder,
extendable portion, drawer, etc. configured to hold objects within
the temperature controlled environment of the chamber) that is
extendable from, and retractable to, the chamber (in a
manually-operated or power-operated manner). The warmer drawer is
also capable of use in attaining and maintaining a desired
temperature(s) for a wide variety of non-food objects (e.g. plates,
towels, garments, etc.). Accordingly, all such features are within
the scope of this disclosure. However, this description is not
intended to be limiting and any variations of the subject matter
shown and described may be made by those of ordinary skill in the
art and are intended to be within the scope of this disclosure.
Referring to the Figures, a non-food warming appliance 10
(hereinafter also referred to as a "warmer drawer 10") is comprised
of an enclosure 20 defining a chamber. The chamber can be made of
stainless steel, plastic, coated metal, glass, ceramic or other
metal or non-metal materials or combination of such materials and
can be of a decorative nature. According to the illustrated
embodiments, the chamber is not intended to be airtight, and is
provided with suitable passageways (e.g. air inlet, air exhaust,
etc.) to foster a desired air flow pattern within the chamber.
The warmer drawer 10 is shown to include a cabinet 14, along with a
top and sides, a bottom, and a back (e.g. "wrapper" etc.), all
which comprise the outer enclosure 20. A cabinet having a single
wall construction may be used in applications where the surrounding
surfaces can accommodate the heat loss, or a double wall cabinet
construction (shown to include an inner cabinet walls 15 having an
insulating material or airspace between the walls) to minimize heat
loss to the external surrounds of the warmer drawer. The inner
cabinet walls 15 defines an interior space or cavity (shown as a
chamber 21) and includes a bottom, sides, top and back. A drawer
structure 13 (e.g. movable holder, extendable portion, etc.) is
extendably and retractably located within the chamber 21 and is
shown to include an access cover assembly 24, drawer guide members
19, object support members 37 and a rear panel 35. The warmer
drawer 10 is also shown to include a heat source such as one or
more heating element(s) 34 (note: a shield may be provided in the
cabinet to provide heat protection from the heat source). A panel
24 (which may be in the form of one or more doors 12) provides
access to the chamber 21 of the cabinet 14.
Although only several possible constructions for the warmer drawer
cabinet have been described, there are many ways to construct a
warmer drawer cabinet according to alternative embodiments. For
example, the chamber can be expanded and configured for a wide
variety or quantity of objects, or for containment of certain
specific items having a particular size, shape or warming
configuration. By further way of example, the cabinet 14 can be
expanded horizontally or vertically and devices for holding objects
(such as hanger(s) described below) could be added to a larger
chamber that could have one drawer with one door front 12, or two
or more door fronts 12 and two or more drawers. According to
another example, vertical expansion of the warmer drawer may
accommodate multiple inverted hangers within an enlarged cavity, or
multiple drawer structures in a single large cavity, or multiple
drawers, or multiple cavities arranged in a "stacked" orientation.
In addition, one or more heating elements 34 could be provided for
proper heating. A non-food warmer drawer could be made with one
drawer 10 and one door, or it could be designed to have two or more
drawers and two or more doors, or any combination of doors and
drawers, and in any desirable shape and size (e.g. tall and narrow,
short and wide, square, rectangular, etc.). (See FIGS. 11-13, and
15).
Referring to FIGS. 2, 6 and 7A-7D, non-food objects O, shown by way
of example as towels, are arranged (e.g. hung, suspended, draped,
etc.) over an object support structure 37, shown for example in
FIGS. 6 and 7A as an inverted V-shape member (e.g. bars, rails,
etc.) to expose a greater portion of the object's O surface area to
the heated air circulating within the chamber and around the
object(s) O. According to alternative embodiments, the support
structure 37 can be made of a perforated material or mesh, as one
way of increasing the open space for the circulating heated air to
reach a greater portion of the object. The support structure 37 in
cross-section may be similar to an inverted "V," inverted "U," "X,"
upright "Y" or other suitable cross-sectional configuration
intended to "spread open" a "draped" object (shown as a towel) in a
manner to allow heated air within the chamber to circulate about
and through the draped object O (see FIGS. 7A-7D). It is believed
that textiles tend to warm-up faster than metals or plastics,
therefore reducing the surface area of a metal support structure is
intended to speed up the warming of textile objects O supported by
a metal support structure. The support structure 37 can also be
composed of rods or a mesh material configured as described above.
The words "inverted "V" or "rail" in this application are not
intended to be limiting and a support structure having any suitable
cross-sectional configuration is intended to be within the scope of
this disclosure.
Referring further to FIG. 6, objects O (shown for example as a
towel or other object formed from textile, cloth, fabric, etc.) are
placed over the support structure 37 which is formed from a
sufficiently rigid material to "open up" or spread and hold the
object(s) O so that circulating heated air within the chamber can
pass into and around the fabric. Each object support structure 37
is preferably attached to supports (such as a cross member--not
shown) at both of the support structure's ends. The support or
cross member may be attached a access cover assembly 24 so that the
support members and objects may be "drawn out" of the chamber by
opening the door or cover assembly. Alternatively, movable fixtures
such as slides or glides, etc. may be coupled to the supports or
cross member and to the chamber 21 so that the support members and
objects may be drawn-out of the chamber independently of the front
door or cover assembly.
Referring to FIGS. 2 and 20-21, the access cover assembly 24 is
shown to comprise an inner panel 25A and outer panel 25B (shown to
form a door 12), with an exhaust fan 84 (including a constant or
variable speed motor) coupled adjacent to the inner panel 25A.
Alternative positions for the exhaust fan 84 can be in the back or
on the sides of the chamber 21 (e.g. near the bottom, etc.). With
the exhaust fan 84 communicating with the door 12, contact pins
(not shown) interfacing between the door and the cabinet 14 (or 15)
co-act to complete a circuit when the door is closed, which
provides power to the fan 84 and the heating element(s) 34 for
heating the chamber 21. Fasteners, such as screws or rivets or the
like are used to assemble the components of the cover assembly 24
together, but other methods of assembly can be used (e.g. snap-fit
connectors, interference fit, etc.). The door 12 may be fixed
directly to the drawer structure and thus movable with the door
structure (such as shown in FIGS. 2, 16 and 25), however, the
door(s) 12 may be hinged and/or slideably coupled to the cabinet to
permit extension of the drawer structure from the cabinet (such as
shown for example in FIGS. 27-28).
Referring further to FIG. 2, vent opening(s) 80 (e.g. slits, slots,
holes, passages, etc.) can also be configured in the cabinet 14 for
expelling air out from the chamber 21 (shown for example as located
on a top panel of the cabinet above the heating element 34 in FIG.
2, but may be provided at the bottom of the cabinet, such as shown
for example in FIG. 18 to provide an alternative air flow pattern).
Air can be vented in any direction (e.g. into, or out of, the
chamber 21) such as by reversing the direction of operation of fan
84, and volume of air circulated through the chamber may be
regulated by the fan speed and the vent apertures 80, which may be
fixed in size, or have an adjustable size (e.g. manually
adjustable, or mechanized in conjunction with controls, etc.).
According to a preferred embodiment, the vent apertures 80 are the
entry points (e.g. inlet, intake, etc.) for fresh air. Any suitable
number of vent apertures can be provided having a fixed size or an
adjustable size. For example, a venting apparatus 81 (as shown for
example in FIG. 2) includes a vent actuator 82 configured to adjust
the size of the vent apertures 80 through use of a plate (shown as
a damper 81) movable by the vent actuator 82 between a closed
position (see FIG. 29) to completely close the vent apertures 80
and an open position to completely uncover vent apertures 80, and
any intermediate position there between (see FIG. 30) as desired to
regulate the flow of air through the chamber. According to any
exemplary embodiment, the vent actuator comprises, for example, a
screw drive 83 (see FIG. 31), or a gear device 87 (such as a rack
and pinion--see FIG. 32), or a solenoid drive 88 (See FIG. 33).
According to alternative embodiments other drive mechanisms may be
used for the vent actuator such as a bimetallic device, or an
electromagnetic device, or other suitable electronically or
electro-mechanically controlled device or other suitable
equivalents of a driver device for adjusting the position of the
damper 81 in relation to the vent apertures 80. The ability to
control the flow of air and moisture within the chamber 21 by an
actuator 82 coupled to a damper-vent apparatus is intended to
regulate the flow of air being exhausted from, or brought in to,
the chamber 21 of the warmer drawer 10. The vent actuator 82 is
controlled by the electronic control system 60 (to be further
described) to permit regulation of the heat, moisture and/or air
flow within the chamber 21, based on user selected inputs (or
pre-programmed inputs) and signals received from sensors
communicating with the chamber.
Referring further to FIG. 2, one embodiment of the non-food warming
appliance 10 is configured to vent heated air in the event of air
movement failure for minimizing impact to objects within the
chamber. With this configuration the heating element(s) 34 are
located at the top or topsides and vent apertures 80 are located
above the heating elements. In the event of blower or fan 84
failure, blockage, or loss of air movement, the heated air within
the chamber rises and vents upward and out through the vent
apertures naturally (e.g. similar to a "chimney" flow arrangement,
etc.) and is intended to protect heat sensitive objects (such as
cloth(s)/towel(s), etc.) inside chamber 21 from heat damage (e.g.
discoloring, burning, etc.). Determination of fan failure, or other
event that may result in excessive heating may be detected by
suitable sensors and the electronic control system may be arranged
to move the vent actuator 82 to a full open position (if not
already open--such as a "fail safe" position, etc.).
Referring further to FIG. 2, the drawer structure 13 includes the
access cover assembly 24, a rear panel 35 and a delivery system
that includes support guide members 19, and can be made of any
suitable material such as stainless steel, plastic, coated metal or
other temperature-resistant materials and can be of a decorative
nature to match (or contrast with) the surroundings desired by a
particular user. The warmer drawer 10 can be configured with a
provision to allow the drawer structure 13 to be pulled partially
or completely from of the inner cabinet 15 to enhance a user's
ability to install/remove objects O (such as for example cloth(s),
or towel(s), etc. on object support members 37) without having to
reach inside the chamber 21 or come in contact with any of the
sensors or heated surfaces. In order to enhance the functionality
and usefulness of the warmer drawer 10, additional accessories may
be included for use within the chamber. For example, a pan 36 (e.g.
tray, holder, etc.) can be provided for wet objects O and
positioned to evaporate the moisture in the object(s) O (such as
cloths, towels, robes, etc.--see FIGS. 8-9 for example).
Additionally, a wire rack 39 (e.g. drying rack, an accessory rack
for footwear or gloves, etc.) can be configured to couple to the
pan 36 to further enhance air circulation and drying of the
objects. The front cover assembly 22 may be provided with any
suitable door configuration, shown for example as hinged front
doors 12. According to any exemplary embodiment, the front cover
assembly permits the user to open the warmer drawer, pulling out
the inside rack 39, drawer structure 13, shelf, or pan 36, and
swinging or folding the door(s) 12 out of the way (or pulling a
panel type door that is fixed to the drawer structure, such as
shown for example in FIGS. 1, 16 and 25). The door(s) 12 can be
hinged rather than fixed panels, a feature which provides the
benefit of having the door(s) out of the way when accessing the
contents within the chamber (see FIGS. 27-28).
Referring further to FIGS. 2 and 8, a heating apparatus, such as
heating element(s) 34 are provided to generate heat and are shown
located at the top of the chamber 21 (but may also be provided
along the sides or other suitable location communicating with the
chamber 21, such as remotely and communicating through a duct,
etc.). In the event of a loss of air movement within the chamber
(e.g. fan failure, etc.), the heated air rises upward within the
chamber and out through vent openings 80, and away from the objects
O within the chamber 21. Although the heating element is shown for
example as a single cal rod type heating element, it should be
understood that other heating elements can replace or be added to
the standard, single cal rod style heating element. Such heating
elements for replacement or addition are understood to include
(among others) convection heaters; axial heaters (e.g. such as
those having a heating element without a fan); wire heating
elements; heat plates; thermal ceramic heaters; flexible heaters
(which are also commonly referred to as thin film heating elements)
and can be formed and bent into any desired pattern or shape. Other
heating elements intended for application as a heating source in
the non-food warmer drawer may include: light sources; inductive
heaters; heat pumps (which can provide heating and cooling);
warming liquids; sonic heat generators; heat exchangers; microwave,
gas and solid fuel products (or any suitable combination thereof).
The above-mentioned types of heating elements are generally within
at least one of the following categories of heat sources: radiant,
infrared, sonic vibration, conduction, inductive, convective,
resistance, and microwave. These heating elements can be placed on
the top of the cabinet (as shown in FIG. 2) or on the side of the
cabinet, or in any other suitable location, including remotely
located and in fluid communication with the chamber of the non-food
warmer drawer. Use of these heating elements in combination with
the electronic control system and appropriate sensors is intended
to improve the heat control and accuracy of the temperature inside
the chamber and achieve a relatively even temperature distribution
or profile throughout the chamber 21. The heating element(s) 34 are
shown to receive a supply of power via the power board(s) 66 (see
FIGS. 3-4) from an energy source 64 such as an AC or DC source
powered in accordance with specifications for a particular warmer
drawer. The use of two or more heating elements 34 can be used to
improve the uniformity of temperature distribution and minimize
thermal gradients within the chamber, and also to reduce start up
times (e.g. multiple heating elements may be activated during the
startup or warm-up phase and then be selectively de-energized or
"cut-back" as the desired temperature is attained, and then perhaps
automatically reenergized to maintain the desired temperature, such
as when the drawer is opened, or due to loading of cold or cool
objects in the clamber, etc.). The use of electronics for elements
of the control system 60 and use of different/multiple heating
elements at strategic locations can greatly improve warm up times
to reach desired temperatures faster. Greater control of
temperature within the chamber is intended to minimize the
amplitude and duration of any temperature overshoots and
undershoots, thus resulting in better temperature control of the
objects to be warmed.
Referring to FIGS. 3-5, an electronic control system 60 for the
warmer drawer is shown according to an exemplary embodiment.
Electronic control system 60 is shown to include electronic printed
circuit boards shown as a power board(s) (shown for example as two
power boards 66 in FIGS. 3-4) and a control board(s) (shown for
example as a single control board 65 in FIG. 5), which describe one
type of electronic control system 66. However, the control board(s)
and power board(s) may be combined into a single board. The control
board 65 of the electronic control system 60 is shown to receive a
power supply from a power board 66 and to include a central
processing unit (shown as a microcontroller 68) that is configured
to receive inputs from various sensors that provide signals
representative of the operation of the warmer drawer (shown for
example as a temperature signal input from a temperature limited 54
or temperature sensor 73), and to review inputs 72 from the user
interface 40 (via an interface circuit) and to provide outputs to
various display devices or indicators shown for example as display
device 49 and to status LEDs that may be provided in the user
interface, display device, or other suitable location on the warmer
drawer for conveying information to the user. The microcontroller
68 is also shown to provide an output to power board 66 for
operation and control of the heating elements 34 and the fan/blower
84 and ventilation system actuator 82 for control and regulation of
heating, airflow within and ventilation of the chamber 21 and
objects O within the chamber 21. The power boards 66 are shown to
receive a power supply input from an energy source 66 (such as a
line input from a conventional power source, etc.) and to
communicate with various sensors (shown as a temperature sensor(s)
73 and a humidity sensor(s) in FIG. 3, and an infrared temperature
sensor 74 in FIG. 4) and to provide signals from the sensors to the
control board 65, and to receive control signals from control board
65 for control and operation of the components of the warmer drawer
10. According to an alternative embodiment, the control board may
also provide suitable output control signals for operation of the
drawer structure of the warmer drawer (such as for use in a
power-operated drawer structure--shown for example in FIGS. 25-26,
to be further described). According to other alternative
embodiments, the sensors may include any suitable sensors for
conveying operating information to the electronic control
system.
The control board 65 of the electronic control system 60 (through
the power board(s) 66) is configured to regulate the electric power
to the heating elements 34 such that the heat output to the chamber
21 can be held substantially constant. In this regard, the
applicants believe that regulating the power and thus controlling
the heat is a significant improvement in controlling temperature in
non-food warmer drawers. This can be accomplished by an electric
thermal-limiting device. For example, microprocessor 68 of control
board 65 is shown to be in communication with a positive
temperature coefficient of resistance (PTC) current/voltage
controller 71 through power board 66 (see FIG. 3). According to an
exemplary embodiment, the electronic control system 60 includes a
positive temperature coefficient of resistance (PTC)
current/voltage controller 71 for controlling the heat and power
requirements and providing rapid response during start-up. The PTC
controller 71 allows current to the heating element(s) 34 and as
temperature gets close to the upper limit, the PTC controller 71
limits the current to the heating element 34, stopping the rapid
rate of heat/temperature increase in the chamber 21, thus
minimizing overshoot. PTC thermistors (thermally sensitive
resistors) are solid state, electronic devices, which detect
thermal environmental changes for use in temperature measurement,
control and compensation circuitry and exhibit an increase in
electrical resistance when subjected to an increase in body
temperature. PTC devices remain in their low resistance state at
all temperatures below the temperature corresponding to the desired
set point. When the temperature corresponding to the desired set
point is reached or exceeded, the PTC exhibits a rapid increase in
resistance thereby quickly limiting current to the heating element
circuitry to minimize temperature overshoot. Once the temperature
within the chamber decreases to a normal operating level, the
device resets to its low resistance state providing full load
current to the heating element. The dramatic rise in resistance of
a PTC thermistor at the transition temperature tends to makes it an
attractive candidate for current limiting applications. For
currents below the limiting current, the power being generated in
the unit is not sufficient to heat the PTC to its transition
temperatures. However, when abnormally high fault currents flow,
the resistance of the PTC increases at such a rapid rate that any
increase in power dissipation results in a reduction in current.
These devices have a resistance temperature characteristic that
exhibits a very small negative temperature coefficient until the
device reaches a so-called "critical" temperature for the upper
limit or set point of the warmer drawer, which is referred to as
the "curie," switch, or transition temperature. As this critical
temperature is approached, the PTC device begins to exhibit a
rising positive temperature coefficient of resistance as well as a
large increase in resistance. This resistance change can be as much
as several orders of magnitude within a temperature span of a few
degrees. Thus as the chamber temperature increases from an ambient
temperature, the PTC device increases in surface temperature
reducing the ability to dissipate heat which results in an increase
in resistance resulting in reducing the current to the heating
element. This increase in resistance and reducing current also
slows down the heat up when coming to the set point. The PTC device
also does not completely stop the flow of current to the heating
element, but rather, limits the current to the heating element.
Thus providing and maintaining a steady temperature by
substantially eliminating on/off "swings" that are characteristic
of other conventional non-food warmer drawers. This design also
provides users with cost savings; since the undesirable "on/off
cycling" with its corresponding overshoots and undershoots is
avoided, the full current draw of the heating element is also
avoided and the warming drawer uses only the required current for
start-up heating and maintaining the desired temperature. According
to other embodiments, the control system includes any one or more
of a micro controller(s), micro technology, integrated circuits,
drivers and microprocessors that may be mounted on one or more
printed circuit boards, to provide the desired functionality of
interfacing with the heating elements, the ventilation system, the
sensors, the display device and the user interface.
Such embodiment providing an electronic control system 60 as
described above is believed to be an improvement over prior art
methods of cycling power "on and off" in an attempt to control the
heat within the chamber. With the electronic control system, the
necessary heat load for the chamber can be determined and then only
that amount of power/heat necessary is supplied. This also can
prevent or minimize temperature overshoots by quick warm-ups and
when "almost reaching" the set point, by limiting the amount of
heat energy when reaching the set point. The ability to better
regulate the electrical power to the heating elements such that the
power output can be regulated will improve accuracy, and similarly
increase or decrease the heat output to the chamber with improved
accuracy. This innovation is also believed to reduce the user's
operating costs in comparison to conventional non-food warmer
drawers. The electronic control system through interaction with the
sensors and user interface can determine the necessary heat load
for the chamber and supply only that amount of power to the heating
elements 34 (in combination with control of air circulation by the
fan 84, and inlet/exhaust by ventilation actuator 82) necessary to
quickly heat the air and objects with chamber 21 to the desired
temperature.
Referring to FIG. 19, a user interface 40 is shown according to an
exemplary embodiment. User interface 40 is intended to permit
convenient operation and control of the non-food warming appliance
10 by a user. User interface 40 is shown to include a display
device 49 that provides the ability to display information to the
operator such as the temperatures and times through the use of
electronics, illumination of indicators such as status LEDs, and
the option of using a mechanical device (e.g. knob, switch, etc.)
to interact with the electronic control system 60 in order to
simplify the user's involvement with the warmer drawer. The ability
to accurately control operation of the warmer drawer without a
"complex" user interface is intended to enhance the ability to heat
an object O to a desired temperature and hold it at that
temperature until needed while minimizing the concern for damage to
the object (such as discoloration or burning, etc.) that might
otherwise be caused by operator error with more complex user
interfaces. According to one embodiment, the user interface may be
a switch (e.g. toggle, rocker, touch, etc.) such as for example, an
"on/off" type switch shown as switch 48 (shown for example on a
remote control device in FIG. 19, and on the user interface 40 in
FIG. 22, but may be located on the cabinet of the warmer drawer or
any other suitable location).
However, through the use of suitable electronics in the electronic
control system, complete user programmability is available if
desired and selected during the design of the warmer drawer. For
example, a user interface 40 for a warming drawer 10 (see FIG. 22),
may be integrated with a display device 49. The user interface 40
is shown as an electronic touch control panel 43 (e.g. touch pad,
key pad, input device, etc.) according to an exemplary embodiment.
The user interface 40 may include any suitable input elements 45
(shown by way of example in FIG. 22 as FAN ON, FAN OFF, FAN SPEED,
TEMPERATURE UP, TEMPERATURE DOWN, TIMER ON, TIMER OFF. LIGHTS ON,
LIGHTS OFF, LIGHTS LEVEL, and four selectable settings marked 1, 2,
3 and 4 (such as pre-programmed settings), for selection and input
of desired operations by a user to an interface circuit on the
control board 65 of the electronic control system 60 for
interaction with microcontroller 68, however any suitable input
elements may be used to suit a particular application. According to
any exemplary embodiment, the user interface 40 may be provided
using any suitable technology such as (but not limited to) a piezo
touch panel, or a capacitance electronic touch control panel (e.g.
made of glass, metal or plastic, etc.) with selection of the
operating function(s) made by touching the surface of the glass,
metal, or plastic to operate any size warmer drawer could be used.
In addition, tactile (membrane switches) touch control panel switch
pad(s) for touch controlling the operations of a warmer drawer
could be used. For any size warming drawer, other types of user
interfaces may include resistance type touch control keypad,
whereby touching plastic, metal, glass, etc. at a location causes a
change in an electrical signal to be measured and the electronic
control system responds to this change. According to any exemplary
embodiment, the user interface may include use of membrane
switches, piezo, capacitance, paddles touch soft switch technology,
paddles touch digital encoder (micro-encoder), capacitive,
infrared, high frequency, magnetic, field effect, charge transfer,
hall technology resistance and inductive. Further, the face panel
of the user interface can be fitted with decorative overlays,
underlays, labels, trim and completed control panel assemblies.
Touch control keypads or panels can be installed flush, raised, or
recessed for use in connection with the electronic control system.
Further, the touch control key pads of the user interface 40 can be
installed in any plane of the warmer drawer 10 (or remote structure
when operated by remote control) with the use of electronics.
According to an alternative embodiment, the display device and the
user interface may be arranged as separate (yet still
intercommunicating) devices at any suitable location on the warmer
drawer.
The components of the user interface 40 may be placed on any
surface to accommodate any design or for matching or simulating the
look of other products that may be associated with the warmer
drawer. The touch control keypads of the user interface 40 and
display device 49 can be placed on the front of a warmer drawer 10
to provide the user with "instant viewing" of the operations and
functions without having to open up the warmer drawer (such as
shown for example in FIG. 22). Touch control panels can be made of
metal, plastic or glass to suit a particular application. The use
of a micro controller or integrated circuits and drivers, PC
board(s), processor(s), and power, and other electronics (shown for
example as a microcontroller 68 in FIG. 5) can be used in the
electronic control system 60 to interface with input codes 72 from
the touch pads of the user interface 40 to control operation of the
components of the warmer drawer 10. Any size from a small to a
large warmer drawer can be fitted for use with a touch type control
pad (e.g. piezo, capacitance, resistance, etc.). Further, any size
from a small to a large warmer drawer can be fitted for use with an
induction touch control pad. The design of the electronics can be
unique or matched to the other looks, aesthetics, appearance or
decor on adjacent or cooperating appliances or structures. The
overall size, design, look and feel of a warmer drawer can be
matched to the size, design, look and feel of any appliance or
structure.
According to another exemplary embodiment, the touch control panels
of the user interface 40 can be remotely controlled in a location
away from the warmer drawer (see FIG. 19). Remote control can be by
wire or by wireless controlling the functions of a warmer drawer.
The touch control panels of the user interface 40 may have graphics
(e.g. pictographs that are unique or specific to the design for the
matching product(s) or specific to the required designs and
functions, etc.).
According to another exemplary embodiment, the display device 49
and/or user interface 40 may be placed on any desired surface of
the warmer drawer or associated structure (e.g. to accommodate any
design for matching or simulating the look of other products the
appliance may be paired with, or to protect the components from
damage, or exposure to adverse environments, etc.). By way of
example, the display device 49 and user interface 40 may be
integrated and arranged to be "hidden" from normal view by the
closing of a sliding panel (which may be spring-biased) or by
integrating the display and user interface with a rotating panel or
L-shaped plate (shown for example as a rotating drum 41 in FIGS.
23A-24B) which may be mounted on a stationary portion of the warmer
drawer or on the drawer portion 13 and repositionable in a variety
of orientations for ease of viewing/operation and for concealment.
This ability to conceal the display/interface, to protect it from
damage, or match other appearances, and having it independent of
the moving drawer but still have a "flush looking" front surface,
or to provide a smooth looking front is intended to enhance the
functionality and options available to a user for operation of the
warmer drawer. Once the user has completed viewing the display or
operating the interface, the user (or the electronic control system
of its own accord) can rotate the drum to a position to conceal the
display/interface and expose a "matching" panel to provide a
smooth-looking or substantially uniform front appearance. According
to one embodiment, electronic sensors may be provided in the
display/interface so that the user can touch the front of the
display/interface for movement to a storage position or for
movement to a viewing/operating position. When the electronic
sensors in the display/interface sense the "touch", the rotation
begins until reaching the stop point (e.g. at the next "position"
of the display/interface), such as the display/interface panel
provides the smooth front. Another way the display/interface may be
moved to the storage position is if the warmer drawer (or another
associated appliance) have been "off" for a predetermined time
period. Once such a predetermined time period has elapsed, the
display/interface may automatically move from the viewing/operating
position to the storage position. A drive device such as a motor or
actuator (shown for example as a drive motor 42 in connection with
the user interface 40 in FIG. 22; however, other suitable devices
for rotating the display assembly can be used to provide movement)
is provided for operation of the repositionable display/interface.
Suitable devices such as switches, stepper motor(s), magnetism, or
a positive stop like metal can be used for the location of "stop
points" for locating the desired positions of the
display/interface. Power and control for operation of the drive
motor 42 may be provided by the micro-controlled via the power
board(s).
The ability to display in a user interface 40 to the operator the
operations, functions, temperatures and times using electronics and
to accurately control these operations is intended to enhance the
ability to hold desired temperature within the chamber 21. The user
interface 40 may include any suitable device for interacting with a
user, such as knobs or other suitable devices for initiating input
codes 72 to interface with the electronic control system 60. For
example, such devices may include loop resistant circuitry which is
designed for use in membrane switches; special edge seal finishing
for design of key pads using membrane switches; ESD/EMI/RFI
shielding; LED, LCD, plasma, dot matrix, and vacuum fluorescent
types displays can be used. In addition, electronic touch control
panels could use a piezo touch panel (keypad) for selection of
operations by the user. Also, a capacitance electronic touch
control panel (keypad) could be user and made of glass, metal or
plastic, to facilitate selection of the operating functions by
"touching" the surface of the glass, metal, or plastic. Another
choice could be tactile (membrane switches) touch control panel
switch pads. For any size warmer drawer 10, a user interface 40 in
the form of a resistance type touch control keypad could be used
whereby touching plastic, metal, or glass at a desired location
causes a change in an electrical signal (such as input signals 72
shown in FIG. 5), is measured, and the electronic control system
responds to this change. Use of membrane switches, piezo, pad-less
touch soft switch technology, pad-less touch digital encoder
(sometimes referred to as a "micro encoder"), capacitive, infrared,
high frequency, magnetic, field effect, charge transfer, hall
technology, capacitance, resistance and inductive devices for the
user interface can be fitted with decorative overlays, under lays,
labels, trim and completed control panel assemblies. Remote control
of warmer drawer 10 functions can be by wire or wireless user
interface 40 devices. Keypads can have graphics specific to the
design for matching other mating products or can be specific to the
required designs and functions of the warmer drawer. The use of an
electronic control system provides the user with better control and
offers more flexible operations than can typically be obtained with
a mechanical control.
Another embodiment of a non-food warmer drawer 10 provides a
factory preset function to be controlled by the electronic control
system or by suitable mechanical controls in communication with an
AC or DC electronic temperature and/or humidity sensor(s) (such as
sensors 73, 74 and/or 77) located for contact or access to a wall
or inside region the chamber 21. The output from the AC or DC
electronic temperature sensors is provided to the control board 65
(i.e. at "temperature/humidity input from power board 66"). A
non-food warmer drawer designed to be controlled by the electronic
control system and equipped with an electronic temperature sensor
located inside the non-food warming drawer or in the chamber such
that the temperature inside or next to the non-food warmer drawer
can be detected accurately and proper output control signals
provided to regulate the heat provided by heating elements 34, the
operation and speed of fan/blower 84 and the position of
ventilation system actuator 82.
Temperature detection through sensors can be accomplished by a wide
variety of technologies such as resistance temperature detectors
(RTD), thermistors, IC sensors, radiation sensors thermometers,
bimetallic, IR and thermocouples. One widely used device for
measuring temperature is the RTD, which provides a low cost option
for use with an electronic control system. Even though RTD sensors
tend to be relatively slower in response than thermocouples, RTDs
offer several advantages over "older style" sensors. For example,
RTDs tend to be inherently stable and have greater thermal shock
capability, which is advantageous when transporting the warmer
drawer to the user. Another advantage is that no special
compensating lead wire or cold junction compensation is usually
needed. After sensing a signal from the RTD, a conditioning device
such as a transmitter is provided to convert the signal from the
RTD/sensor to an electrical signal recognizable by the control
board. The temperature transmitter may be of a type such as a four
wire, three wire or a two wire type, but other types can be used.
The optimum form of connection of RTDs is the four wire circuit,
since it removes the error caused by mismatched resistance of lead
wires. According to an exemplary embodiment, any/all of the above
components may be provided on a chip or circuit board to be placed
in a desired location for detection of temperature within the
chamber and to provide data/information to the control board for
controlling the function of the components of the warmer
drawer.
According to an alternative embodiment, distributed temperature
sensor(s) (which offer the next generation fiber optic distributed
temperature sensor that sense temperature at a plurality of points
along a stainless steel sheathed fiber and feature a typical
resolution of about 0.5.degree. C. and a spatial resolution of
about 1.5 m) can be used. The fiber can range up to 2,000 m and can
be coiled at specific points of interest. Fiber can be sheathed
with a nonconductive polymer for intrinsic applications. Thus, the
distributed temperature sensor provides the ability to profile the
chamber of a non-food warmer drawer for detection of temperatures
throughout the chamber at a great number of discrete locations.
Response times also tend to be shorter and this permits the control
board to process a more complete target zone (such as an entire
chamber space) rather than the one zone within the space. Use of
the distributed temperature sensor is also intended to permit the
manufacturer to customize the zones within the chamber by placing
more temperature sensing points in desired areas for detection.
According to one embodiment of a simplified control scheme, the
temperature of the chamber 21 or temperature of objects O placed
into the chamber 21 can be detected accurately through the
temperature sensor(s) and only an "on/off" type switch (such as a
switch 48 shown for example as located on a remote control device
in FIG. 19) may be provided for (or with) the user interface. Any
suitable temperature sensor, such as an electronic,
electromechanical, or mechanical type of temperature sensor can be
used for a temperature sensor 73 for detecting temperature,
resistance, or power for the control of the temperature of a
chamber 21 in the non-food warmer drawer 10. A non-food warmer
drawer 10 having factory presets can be controlled by a temperature
control device 54 such as a fixed temperature thermostat,
thermal-disk, thermal protector, thermal cutoff, or electronics,
electromechanical, or mechanical temperature controller/sensor. A
non-food warming drawer 10 can also have the ability to detect
objects O placed inside the chamber and then set temperature(s) for
maintaining a desired temperature of the object.
For example, a non-food warmer drawer with object detection on a
target surface may include an infrared temperature sensor (shown as
an IR sensor 74 in FIGS. 4 and 16) that collects a small amount of
energy (usually about 0.0001 watt) radiated from the target object,
and generates an electrical signal that is amplified by a precision
amplifier and converted into voltage output. Sensor 74 is intended
to be capable of detecting the presence of an object and the
temperature of the object and provide an appropriate output signal.
The signal is digitized an analog-to-digital converter on the
control board (not shown), and an arithmetic unit (not shown) on
the control board solves a temperature equation based on Planck's
Radiation Law, and compensates for the ambient temperature and
emissivity resulting in a temperature reading within a fraction of
a second after a user places the object in the field of the IR
sensor (i.e. within the chamber 21). Using this technology one can
measure the temperature of an object within the chamber or cover
the complete surface of the chamber from a 5 meter distance as long
as a "field of view" of the sensor is filled by the target. Also,
many IR sensors 74 measure in the 8 um to 15 um wavelength band
where the atmosphere is almost totally transparent. Such IR sensors
74 can operate in complete darkness and can usually penetrate PE
film (for example: a plastic trash bag or saran wrap). The IR
thermometer sensor 74 can also be used to detect the presence or
absence of an object in the chamber. IR sensing can measure objects
that move, rotate, or vibrate (e.g., web process or any moving
process). Such IR sensors typically do not damage or contaminate
the surface of the object, and measure (e.g. detect, sense, etc.)
the temperature of the object and not other parts or surfaces of
the chamber of the non-food warmer drawer. An IR detector can also
be used for detection of excessive heating (such as fire or other
undesirable condition) in the chamber 21 of the non-food warmer
drawer 10. The use of thermal sensing technology such as RTDs
(resistance temperature detectors), integrated circuit sensors
(IC), thermistors, IR thermometers, bimetallic, and thermocouples
can also be used. Alternatively, other sensors like photoelectric,
photon, optics, indium-gallium-arsenide, and thermal detector could
be used in place of IR for the detection of objects within the
chamber.
According to any exemplary embodiment, the type of sensor or
detector used to monitor temperature of the objects and/or chamber
may comprise electronic and/or mechanical technologies. Factory
selected settings of the electronic, electromechanical, or
mechanical controls for the warmer drawer may be provided to
maintain the desired temperature(s) within the chamber as sensed by
the temperature-sensing device(s) 73 within a predetermined desired
range of operating temperatures or set points. The sensor 73 can be
mounted on an electronic board or it can be attached to any wall or
location within the chamber where detection of the temperature can
be made (see for example FIG. 16). The ability to better detect the
temperature within the chamber helps to improve the response time
to temperature changes within the chamber, so that the temperature
may be more accurately controlled and reduce the effects of
temperature overshoot and undershoot by providing a more steady
temperature stream. Any electronic, mechanical or electromechanical
sensor 73 can be used for detecting temperature, resistance, or
power for detection and control of the cavity temperature in
cooperation with the electronic control system. Such temperature
sensors 73, which can be used are, but not limited to: temperature
sensors, thermostats, thermal, temperature controls, thermal
protectors, thermal cutoffs, thermal switch, thermal couples,
adjustable thermostats, PC Boards thermostats, hermetically sealed,
time delay relay, bulb and capillary, cold controls, electronic
controls, bimetallic, pressure switches, creep action thermostats,
controllers, manual reset, automatic reset, disc thermostat, snap
action switch, RTDs (resistance temperature detectors), NTC
thermistors (negative temperature coefficient of resistance), PPTC
thermistors (power positive temperature coefficient of resistance)
may be provided and configured for interfacing with the electronic
control system.
According to another embodiment, the user interface device 40 used
to activate and operate the non-food warmer drawer 10 can be
remotely located, i.e., not on the warmer drawer 10. Remote control
or portions of the control can communicate by wire or wireless to
operate the warmer drawer 10. A remote control unit 75 can be used
as a hand-held unit and can also be placed in a receptacle
proximate the non-food warming appliance 10 (see FIG. 19). The
remote control unit 75 is configured to communicate with a receiver
79 located at any suitable location on the warmer drawer (and shown
on a door 12 by way of example in FIG. 19) and intended to
communicate user input selections 72 to the microcontroller 68 of
the control system 60 for control and operation of the warmer
drawer 10. According to an alternative embodiment, a remote sensing
and receiving system may be provided including a sensor(s) and/or a
remote receiver along with a remote panel at a different location.
The sensor(s) would include a transducer disposed to sense the
desired physical parameter in the non-food warmer drawer. The
transducer will generate an electrical signal representative of the
physical parameters and apply the data to a processor. In response,
the processor drives a digital display, which produces visual
indications of these parameters. The processor also provides
communication between the sensor(s) and the remote receiver to
control operation of the non-food warmer drawer. The receiving unit
controls the non-food warmer drawer through signals for (among
others) turning the unit on, to adjusting the speed of the
blowers/fan and temperature as well as on/off times. The sensor(s)
and receiver(s) could both have a transmitter and/or receiver to
enable communication through signals. A remote sensing and
receiving system (or detecting and display system) may also be
configured as a remote keypad apparatus that can include a display
and a remote transducer unit having a temperature sensor unit or
other transducer exposed to the non-food warmer drawer. The
temperature sensor unit can be mounted in or near the non-food
warmer drawer such that proper detection can be made. However,
those skilled in the art will appreciate that the temperature
sensor unit may assume any suitable location, which allows it to
sense the temperature in the non-food warmer drawer. The
temperature sensor could also be configured to convert temperature
readings into an electrical signal representative of the heating
zone for transmission to the remote display/control unit. In
response to a sensed temperature, the data is displayed and
transmission of operation requirements is sent to the non-food
warmer drawer for processing and operation of non-food warmer
drawer functions.
Referring further to FIG. 2, another embodiment of a non-food
warmer drawer 10 provides an air circulation system including a
blower or fan 84 (shown for example without an integral heating
element attached to the fan). The fan 84 is shown secured to the
inside of the chamber 21 (but alternatively may be remotely located
and in fluid communication with the chamber through a passageway
such as a duct), to circulate heated air and/or draw air in/out of
the chamber, thereby providing better heat control and improved
response time. Circulating and exchanging air within the cavity is
intended to reduce "hot spots" within the chamber. Air movement
within the chamber 21 occurs as air is exhausted or vented from the
chamber. Venting of air from the chamber 80 is intended to help
control humidity levels within the cavity. Fan 84 may be provided
with a variable speed motor to provide varying air flow rates as
needed to control moisture or humidity levels by introducing fresh
(e.g. ambient) air into the chamber. In addition, circulating the
air within the cavity is intended to provide a more uniform
temperature distribution and minimal temperature gradient
throughout the chamber. The resulting air movement from a constant
speed or variable speed fan can help hold a more uniform
temperature throughout the chamber. Temperature sensors 73 and
humidity sensors 77 placed in the chamber can facilitate control of
the fan 84 and venting 80 in the chamber. Humidity and temperature
sensors located in the chamber are configured to provide signals to
the electronic control system 60 which provides a signal to control
operation of the fan 84 (e.g. on/off and/or speed control, etc.),
position of the ventilation actuator 82 (e.g. for regulating
moisture/humidity and/or heat within the chamber), and control of
power to the heating elements 34.
The humidity sensor(s) 77 may be any suitable type of humidity
sensor for interfacing with the electronic control system and
providing a signal representative of relative humidity within the
chamber. For example, the humidity sensors may be HIH Series
humidity sensors such as those commercially available by Honeywell.
Another type of humidity sensor is a thermoset polymer-based
capacitive sensor. Another type is a thermoset polymer-based
capacitive relative humidity (RH) sensor which directly detects
change in "relative saturation" as a change in sensor capacitance
with fast response, high linearity, low hysteresis and long term
stability. Relative saturation is generally the same as ambient
relative humidity when the sensor is at ambient temperature.
Because this is usually the case, sensor capacitance change is then
a measure of RH change. Capacitive RH sensors dominate both
atmospheric and process measurements and are capable of operating
with a desired accuracy down to about 0% RH. Because of their low
temperature effect, they are often used over side temperature
ranges without active temperature compensation. Thermoset
polymer-based capacitive sensors, as opposed to thermoplastic-based
capacitive sensors, allow higher operating temperatures and provide
better resistivity against chemical liquids and vapors such as
oils, common cleaning agents, ammonia vapor, etc. in concentrations
commonly used to clean appliances such as warmer drawers. In
addition, thermoset polymer RH sensors usually provide the longest
operating life. Relative humidity/temperature and relative humidity
sensors can be configured with integrated circuitry to provide
on-chip signal conditioning. These sensors contain a capacitive
sensing die set in thermoset polymers that interact with platinum
electrodes. Other operating sensors useful in the warmer drawer are
resistive and thermal conductivity humidity sensors.
Another embodiment of a non-food warmer drawer 10 provides a mobile
pedestal type warmer drawer with drawers, slides, or doors for
heating non-food objects O. The warmer drawer is shown for example
as combined with a mobile pedestal 22 (see FIG. 14) to provide a
non-food warmer drawer that is shown as not built into a wall,
cabinetry, structural member, immovable island or other non-mobile
structure. The warmer drawer or its pedestal 22 is intended to be
self-supporting and rests upon its own structure (shown for example
as footpads 17, foot pegs, wheels 16, casters 18 or the like,
etc.). The pedestal 22 can be removed when not in use or it can be
permanently attached to the warmer drawer. The warmer drawer 10 can
be removed and placed on any desired surface for use and then
returned to the pedestal 22, or the warmer drawer may remain
coupled to its pedestal 22 and immobilized during use (e.g. by
wheel locks, chocks, etc.). The mobile frame of the pedestal 22 may
be made of wood, metal, plastic, composite material or any
combination of such materials intended to provide a lightweight yet
sturdy support and transport structure. Another embodiment of the
warmer drawer can provide for use indoors or outdoors, such as by
weather-resistant features (e.g. sealed touch pads, sealed
electronic modules, gasketed door panels, location of vent
apertures on an underside of the cabinet, etc.). A mobile non-food
warmer drawer can also be installed into a mobile island or cart to
be used for warming non-food objects O. According to any exemplary
embodiment, the warmer drawer as shown and described (e.g. mobile
or stationary, etc.) may be used in any desirable location for any
suitable application. For example, the warmer drawer may be used in
kitchens (institutional, commercial or residential) for warming
non-food items, or may be used in other applications such as
hotels, resorts, spas, golf courses, cruise ships where it is
desirable to maintain the temperature of non-food objects for the
comfort or convenience of users, customers, consumers, guests,
staff, etc.
Another embodiment of a non-food warmer drawer 10 provides a
factory preset control scheme with pre-programmed temperature set
point(s), pre-programmed set time(s), and/or pre-programmed set
operation(s) as well as preset of time(s) both on and off for
users, as part of the electronic control system 60. Timed off
control can be provided if a user desires the unit to automatically
control the off time of the warmer drawer (such as for automatic
shutoff after a predetermined time period, such as, for example, 4
hours), which can be preset by the factory to suit a user's
particular application. The advantage of using factory presets is
to provide a warmer drawer 10 that is capable of controlling these
items rather than a user, and helps to minimize "user error" or
other mistakes in establishing the proper settings. Factory presets
can include one, two or more functions, operations, set point(s)
with essentially limitless programming entered into electronic
control system 60 for control of these items without user
involvement (e.g. other than turning the warmer drawer "on" or
"off" and/or selecting one or more preset options). The
microcontroller 68 of the electronic control system may be
preprogrammed with the desired temperature set point(s), set
time(s), and operation(s), function(s), etc. to simplify operation
of the warmer drawer for a user's intended application(s). For
example, timed on/off control can provide the ability to control
the on/off time of the warmer drawer, and on/off time(s) can be
almost infinitely set with the use of electronic control system.
This pre-programmability provides the advantage of being able to
enter different functions or operations (e.g. more than one) into
the electronic control system and have the warmer drawer control
all the desired functions.
Another embodiment is configured to use scent-imparting substances
(e.g. perfumes, air fresheners and other additives, etc.) that
provide desirable fragrances or aromas to the objects O within the
chamber. A depository 86 (see FIG. 8) in gaseous communication with
the chamber 21 is shown schematically to receive such
scent-imparting substances. The depository 86 may be a pan in
contact or proximity with the heating element 34 or configured for
evaporative dispersion of the scent at any desirable location for
imparting a scent to the objects. Adding desirable fragrances can
also be accomplished by venting or ducting from a different chamber
or ducting from outside the cavity or by placing the scent inside
the chamber at any desirable location.
Another embodiment of a non-food warming drawer is configured with
thermoceramic technology functioning as the support structure and
heating apparatus in place of the inverted V or cal-rod type
heating element(s). With thermoceramic technology, the non-food
objects to be warmed are placed over a thermoceramic coated heating
plate or thermoceramic coated rail to heat objects O (such as
towels and the like) from the "inside-out." Thermoceramic heating
elements are generally self-controlling (e.g. by design with a
predetermined watt density according to a desired temperature) and
are thus particularly suited for use in a non-food warmer drawer to
further minimize the potential for overheating of the objects. The
non-food warmer drawer with thermoceramic heating elements may be
used with (or without) a fan for exhausting heat and/or moisture
from the chamber.
Referring to FIGS. 25-26, a non-food warmer drawer 10 is shown
according to an exemplary embodiment having a powered extendable
drawer structure 13 (e.g. "servant drawer"--for convenient access
for loading or removal of objects from the chamber) having the
ability to open or close by the touch of a user or by some signal
device so that a user can open or close the warmer drawer without
having to pull or push on a handle or the like through the travel
range of the drawer structure. Activation of the warmer drawer can
be by touching the front door, breaking a beam, interrupting a
signal, or having a feed back signal to a sensor/detect with no (or
minimal) hand held control or contact with the warmer drawer or
drawer structure. An activation system is provided to control
operation of the drawer structure by interfacing with suitable
sensors, the electronic control system 60 and a drive system 99.
The drive system is shown for example to include a motor-driven
drive screw 92 rotatably coupled to the cabinet 15 (such as by a
bushing or the like--shown for example as a bearing 98) and
interfacing with a threaded sleeve (shown as collar 97) coupled to
the drawer structure 13 for extending and retracting the drawer
structure 13 from the cabinet 15. Extendable support members (shown
as telescoping glides, or guides 19) are provided to guide movement
of the drawer structure along its path of travel and to support the
weight of objects in the drawer structure. According to one
embodiment, an activation system is shown as a hall sensor 95 and a
magnet 97 (shown schematically in FIG. 17) used to determine the
"stop points" and/or "start points" for movement of the drawer
structure and to initiate signals for opening and/or closing the
drawer structure 13. Note that the sensor 95 is shown for example
on the cabinet 20 and the sensor 95 is shown for example on the
drawer structure 13, however, the sensor may be provided on the
drawer structure and magnet may provided on the cabinet, or the
sensor and magnet may be provided on other suitable structures and
arranged to interface with one another to provide "stop" and/or
"start" points or other indications/signals for control of the
opening and/or closing the drawer structure. For example, when
opening of the drawer structure 13 is desired, the activation
system receives an input and initiates a drive system 99 and the
sensor 95 detects the initial movement of the magnet 97 away from
the sensor 95, which may provide a signal to the display device 49
to indicate position of the drawer structure 13 and may also
initiate operation of a drive system 99 (if movement of the
extendable portion was manually initiated) to move the drawer
structure 13 from a closed position to an open position. (see FIG.
25). As the drawer structure 13 approaches the open position,
another magnet (not shown) may approach the sensor 95, which then
initiates a signal (e.g. a stop point) to terminate movement of the
drawer structure 13. Movement of the drawer structure from the open
position to the closed position may also operate in a reverse
manner. For example, upon activation the drive system 99 moves the
drawer structure 13 toward the closed position, which is detected
by the sensor as the (second) magnet moves away from the sensor 95
(and initiates operation of the drive system if manually activated)
in a closing direction until sensor 95 detects the approach of
magnet 97, such that the field of the magnet detected at the sensor
indicates that the extendable portion has reached the desired
position, such as the closed position (another stop point), which
may correspond to any particular position (e.g. compression of a
gasket between the extendable portion and the cabinet, etc.). Also,
a change in resistance or other suitable indication can be used to
determine the stop points. According to the illustrated embodiment
in FIG. 25, a motor-driven drive screw system 99 is employed to
move the drawer structure 13 open and closed (however, any suitable
drive system such as a motor with a wire, cable, pulleys, etc. can
be used). According to an alternative embodiment, a switch (or
other suitable device such as light-beam sensors, resistive or
inductive touch pads, etc.) can be used to operate the drawer
structure and may be located on the unit or it can be remotely
located for ease of operation and use, and can be operable to
energize any suitable drive device for extending and retracting the
drawer structure. According to other alternative embodiments, any
suitable sensors and signals may be used to initiate opening or
closing of the drawer structure. For example, the signal may be a
sound, a voice, a noise signal (e.g. clapping or banging, etc.)
interrupting a steady state condition; interrupting a beam of
visible light or non-visible light; touching a surface which
resistance increases or decreases providing a signal to a sensor
for activation; force activation by pushing on the door front; and
by a remote control signal such as a hand held control using a
radio frequency or light beam, cooperating with suitable sensors.
These and other methods can be used to activate the drive system
for opening and closing the drawer structure of the non-food warmer
drawer. By providing an activation system cooperating with a drive
system responsive to selected stop points and start points, a user
has the ability to actuate the extendable portion (e.g. by touch,
interruption of a signal, switch operation, etc.), to which the
warmer drawer 10 responds by opening and providing access to the
drawer structure 13 and chamber 21 without having to manually pull
or push the drawer structure throughout its travel range to access
the objects. According to another embodiment, the activation system
may detect an increase in resistance as the motor of the drive
system 99 approaches (or reaches) the stop point and provide an
output signal to stop the motor (or reverse the direction of the
motor, or other desirable control action). According to a further
embodiment, a stepper motor may be provided so that the number of
turns can be counted by the activation system to determine the stop
point and provide an appropriate output signal to control operation
of the drawer structure.
According to any exemplary embodiment, the non-food warmer drawer
as shown and described herein in intended for use in any suitable
facility or room, such as commercial establishments (e.g. a
restaurant, a resort, a spa, a club, a hotel, a pool, a salon,
etc.) or institutional establishments (e.g. hospitals or other
patient care facilities) or in residential applications (e.g. a
bathroom, a kitchen, a dining room, an outdoor recreation center,
pool-side patio, etc.) or any other suitable location selected by
the user.
According to any exemplary embodiment, a warmer drawer is also
disclosed for use in stationary or mobile applications in any
desirable environment and is provided with an electronic control
system that permits control based on user inputs from a user
interface arid/or pre-programmed options that permit a user to
operate the non-food warmer drawer with "the push of a button." The
control system interfaces with a heating system (having one or more
heating elements within the chamber or remote from the chamber, and
that receive electrical power in a continuously variable and
regulated manner to provide precise temperature control within a
chamber), a ventilation system (including an air flow device such
as a variable speed fan/motor, and a variably positionable
damper/vent device driven by an actuator for air, heat and/or
humidity control), a user interface (locally-controlled or
remote-controlled) to permit a user to control the operation of the
warmer drawer in a simple and convenient manner, and a display
device arranged to provide information to a user (e.g. in the form
of alpha-numeric text messages (stationary or scrolling) and/or
graphic images, etc.).
The construction and arrangement of the elements of the non-food
warmer drawer as shown in the illustrated and other exemplary
embodiments is illustrative only. Although only a few embodiments
of the present inventions have been described in detail in this
disclosure, those skilled in the art who review this disclosure
will readily appreciate that many modifications are possible (e.g.,
variations in sizes, dimensions, structures, shapes and proportions
of the various elements, values of parameters, mounting
arrangements, use of materials, colors, orientations, circuit form,
type and interaction, use of sensors, etc.) without materially
departing from the novel teachings and advantages of the subject
matter recited herein. For example, elements shown as integrally
formed may be constructed of multiple parts or elements, the
position of elements may be reversed or otherwise varied, and the
nature or number of discrete elements or positions may be altered
or varied. Other substitutions, modifications, changes and
omissions may be made in the design, operating conditions and
arrangement of the preferred and other exemplary embodiments
without departing from the scope of the present inventions.
The order or sequence of any process or method steps may be varied
or re-sequenced according to alternative embodiments. In the
claims, any means-plus-function clause is intended to cover the
structures described herein as performing the recited function and
not only structural equivalents but also equivalent structures.
Other substitutions, modifications, changes and omissions may be
made in the design, operating configuration and arrangement of the
preferred and other exemplary embodiments without departing from
the spirit of the present inventions as expressed in the appended
claims.
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